Note: Descriptions are shown in the official language in which they were submitted.
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TOOL FOR WORKING SHAPED, HOLLOW METAL
TUBING TO ACHIEVE AN END REDUCTION
CROSS-REFERENCES
The subjection application claims the priority benefits of U.S. Provisional
Patent
Application having Serial No. 60/040,835 filed on March 19, 1997, entitled:
"Tool for
Swaging Metal Tubing, and Integral Tubular Framing System Incorporating Swaged
Metal
Tubing."
BACKGROUND
1.0 Field of the Invention
The present invention relates generally to a tool for working shaped, hollow
metal
tubing and, more particularly, to a tool for working shaped, hollow metal
tubing to achieve
an end reduction in the tubing.
2.0 Related Art
In the metal fabrication industry it is often necessary or advantageous to
join
adjacent lengths of hollow metal tubing to one another, as part of various
structures. It is
particularly advantageous to utilize either square or rectangular metal tubing
in many
applications, because of their shape and associated mechanical strength. Known
methods
of reducing square and rectangular metal tubing have typically utilized one or
more dyes.
With this form of reduction, one end of the square or rectangular tube is
crushed by the
force created by various configurations of press equipment, with the size of
the reduction
being determined by the die design. This method of end reduction of square and
rectangular tubing is subject to the following disadvantages. In the first
instance, the end
reduction of the tubing may require several "hits" or applications of the
press equipment
to achieve the desired reduction, with each application adding to the
manufacturing cost.
Furthermore, the crushing force of the press equipment may cause excessive
andlor non-
uniform deformation of the tube end. More specifically, one or more of the
sides of the
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tubing may become concave, thereby reducing the overall strength of the tube
and
detracting from the smoothness of the transition between the original shape
and the
reduced end. In certain instances, the excessive and/or non-uniform
deformation may be
so severe that the reduced end of the tube is not capable of insertion into a
tube of the same
size prior to reduction, as intended.
Due to the foregoing problems associated with the use of dies to end reduce
square
and rectangular tubing, connections of adjacent lengths of like-sized square
and rectangular
tubing are generally accomplished by inserting a smaller tube inside the two
adjacent like-
sized pieces of tubing, and then securing the joint by fastening each section
of the outside
tubing to the inside tube. The inside tube, as well as the required fasteners,
add to the cost
of this method of joining sections of square or rectangular tubing. Another
disadvantage
associated with this technique is that the strength of the joint is limited to
the strength of
the included fasteners.
In view of the foregoing disadvantages associated with known methods of
connecting square and rectangular metal tubing, there is a continuing need for
improved
methods of joining adjacent sections of shaped metal tubing, such as square
and
rectangular tubing.
SUMMARY
In view of the foregoing needs, the present invention is directed to a tool
for
working a shaped metal tube having a hollow interior and an outer surface to
produce an
end reduction in the tube. The tool of the present invention may be configured
to achieve
an end reduction in metal tubes having various shapes including square,
rectangular, oval
and D-shaped. In each embodiment, the tool achieves a substantially uniform
reduction,
over a predetermined longitudinal length, of the end portion of the tube so
that the reduced
end retains its original shape. Accordingly, the reduced end may be inserted
into a non-
reduced end of a tube having the same shape and size. The end reduction of the
shaped
tube is achieved in a single pass of the tube into the tool. Accordingly, the
tool provides
a simple, fast and economical means for uniformly reducing the end of a tube
to permit the
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tube to be joined to a similarly shaped and like-sized tube having the same
outside
dimensions prior to reduction.
The tool of the present invention, facilitates the use of metal tubing in a
wide
variety of metal fabrication applications. For instance, the use of square and
rectangular
tubing, having reduced ends achieved by the tool of the present invention, may
provide a
flat surface area for mounting which is advantageous in many applications.
Also, since the
tool of the present invention may be applied in a production setting capable
of relatively
high speed production and relatively low cost, the tool of the present
invention may
warrant the redesign of many existing products to take advantage of the use of
metal tubing
sections which may be joined to one another in a simple and economic fashion.
Furthermore, the tool of the present invention will permit a wide variety of
new product
ideas and designs.
According to a preferred embodiment of the present invention, the tool
includes a
head having a longitudinally extending interior cavity and a plurality of
roller cavities each
communicating with the interior cavity, and a plurality of grooved rollers,
each rotatably
mounted within one of the roller cavities. Each of the grooved rollers has a
periphery
which extends into the interior cavity and is configured, i.e., positioned and
sized, to
engage a portion of the outer surface of the tube as the tube passes into the
interior cavity
of the head, thereby forcing the end portion of the tube to be reduced. The
head further
includes a mandrel disposed within the interior cavity of the head, with the
mandrel
permitting the end reduction of the tube to be accomplished without collapsing
the reduced
end of the tube. The mandrel preferably comprises a solid rod having a
polygonal cross-
sectional shape which varies with the shape of the tube to be reduced.
The head includes a base block, a spacer portion connected to the base block
and
a face block portion connected to the spacer portion. These components of the
head may
be made as a unitary construction or alternatively may be fixedly attached to
one another
by conventional fasteners. The base block, spacer portion and face block
portion combine
to define the interior cavity and the face block portion includes the roller
cavities and a
plurality of face blocks configured to define the roller cavities.
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Each of the grooved rollers is rotatably mounted on a roll pin which is
secured
within adjacent ones of the face blocks of the head. The periphery of each of
the grooved
rollers includes a centrally disposed, generally V-shaped portion which is
effective for
engaging a portion of the tube, such as a corner portion of a square or
rectangular tube, as
S the tube passes into the interior cavity of the head. The periphery of the
grooved rollers
further includes a pair of beveled end surfaces extending from opposite sides
of the
centrally disposed V-shaped portion.
In one preferred embodiment, having particular application for reducing the
end of
a substantially square tube, the tool includes four of the grooved rollers,
with two of the
rollers being rotatable in a substantially horizontal plane and the remaining
two rollers
being rotatable in a substantially vertical plane. In this embodiment, each of
the end
surfaces of each grooved roller is disposed in close proximity to one of the
end surfaces
of an adjacent one of the rollers, whereby the plurality of grooved rollers
substantially
encapsulate the square tube as the square tube engages the rollers. In this
embodiment, the
mandrel has a generally square cross-sectional shape. The mandrel includes at
least one
longitudinally extending lead- in chamfer to facilitate insertion of the
mandrel within the
hollow interior of the tube.
In another preferred embodiment, which is particularly suited for reducing the
end
of a substantially rectangular tube, the tool includes four of the grooved
rollers and further
includes a pair of flat-area rollers, with each flat-area roller being
disposed laterally
between a pair of the grooved rollers. Each of the flat-area rollers is
effective for engaging
one of the relatively long sides of the rectangular tube as the tube passes
into the interior
cavity of the head. In this embodiment, each of the flat-area rollers is
rotatable in a
substantially vertical plane, while each of the grooved rollers is rotatable
in a plane which
is inclined relative to vertical. The four grooved rollers and two flat-area
rollers are
disposed relative to one another so as to substantially encapsulate the tube
as the tube
passes into the interior cavity and engages the rollers. In this embodiment,
as well as the
previously discussed embodiment, each of the rollers is preferably made of
tool steel.
Each of the flat-area rollers may include a pair of substantially cylindrical
end
portions and a raised, substantially cylindrical central portion extending
between the end
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portions, with the raised, central portion extending radially beyond the end
portions. The
incorporation of the raised, central portion may vary with application of the
tool and is
particularly useful when the length of the long side of the rectangular tube
is substantially
longer than the length of the short side of the rectangular tube. The raised
portion is
effective for engaging the long side of the tube and facilitating the end
reduction of the
tube. One of the flat-area rollers is disposed above the mandrel, with the
other being
disposed below the mandrel. In the embodiments having flat- area rollers which
include
the raised, central portion, the mandrel has a pair of longitudinally
extending grooves, with
one of the grooves being formed in the upper surface of the mandrel and the
other groove
being formed in the lower surface of the mandrel. Each of the grooves has a
shape which
is complimentary to the shape of the raised, central portion of one of the
flat-area rollers.
The tool may further include a means for maintaining a substantially uniform
shape
of the reduced end of the tube, with the means for maintaining comprising a
rake disposed
within the interior cavity of the head. The rake includes an aperture
extending
therethrough and communicating with the interior cavity. The aperture includes
a forward,
flared portion and a tapered bore extending longitudinally rearward from the
forward,
flared portion. The flared portion serves as a lead-in while the tapered bore
forces the
reduced end of the tube to maintain the desired shape and size. The rake may
be used in
conjunction with any of the previously described embodiments. When the rake is
included, the mandrel extends longitudinally through the aperture of the rake
and into the
base block.
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BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects and advantages of the present invention will
become better understood with regard to the following description, appended
claims and
accompanying drawings wherein:
Fig. 1 is a perspective view illustrating a tool for working a shaped metal
tube
having a hollow interior and an outer surface to produce an end reduction in
the tube,
according to a first embodiment of the present invention;
Fig. 2 is a front elevational view further illustrating the tool shown in Fig.
1;
Fig. 3 is a plan view further illustrating the tool shown in Figs. 1 and 2;
Fig. 4 is a side elevational view further illustrating the tool shown in Figs.
1-3;
Fig. 5 is a perspective view of a square metal tube having an end reduction
achieved by the tool shown in Figs. 1-4;
Fig. 6 is a perspective view illustrating a tool for working a shaped metal
tube
having a hollow interior and an outer surface to produce an end reduction in
the tube,
according to a second embodiment of the present invention;
Fig. 7 is a front elevational view further illustrating the tool shown in Fig.
6;
Fig. 8 is a plan view further illustrating the tool shown in Figs. 6 and 7;
Fig. 9 is a side elevational view further illustrating the tool shown in Figs.
6-8;
Fig. 10 is a perspective view of a rectangular tube having an end reduction
achieved
by the tool shown in Figs. 6-9;
Fig. 11 is a schematic view of a system for achieving an end reduction in a
shaped
metal tube, with the system incorporating one of the embodiments of the tool
of the present
invention.
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DETAILED DESCRIPTION
Referring now to the drawings, Figs. 1-4 illustrate a tool 10 according to a
first
embodiment of the present invention. As shown in Figs. 1-4, tool 10 is
configured to
achieve a swage, extrusion or end reduction in a square, hollow metal tube 12
shown in
Fig. 5. In other embodiments, tool I O may be reconfigured to achieve an end
reduction
in metal tubes having other shapes, such as rectangular, oval or D-shaped
tubes as
subsequently discussed. The square, hollow tube 12 has a hollow interior 14
and an outer
surface 16 having a substantially square shape. The outer surface 16 includes
four corner
portions 18 which extend along the longitudinal length of tube 12. As shown in
Fig. 5,
tube 12 includes an end portion 20 which has been reduced in size by tool 10,
as
subsequently discussed, relative to the original size of a remaining portion
22 of tube I2.
As fiirther shown in Fig. 5, the reduced end portion 20 has a substantially
uniform square
1 S shape which is substantially the same as that of the remaining portion 22.
The reduced end
portion 20 may be inserted into a non-reduced square tube 24 having the same
size as that
of the remaining portion 22 of tube 12.
Tool 10 includes a head 30 having a longitudinally extending interior cavity
32 and
a plurality of roller cavities 34. Each of the roller cavities 34 communicates
with a forward
portion of the interior cavity 32. The head 30 includes a base block 36, a
spacer portion
38, and a face block portion 40. In the illustrative embodiment the spacer
portion 38
includes a pair of spacer blocks 42 which are laterally spaced apart from one
another. The
face block portion 40 includes four face blocks 44 which are configured to
define the roller
cavities 34. In the illustrative embodiment, the face block portion 40, spacer
portion 38
and base block 36 are fixedly attached to one another by a plurality of
conventional
fasteners such as bolts 46. Each of the bolts 46 passes longitudinally through
one of the
face blocks 44, through the adjacent one of the spacer blocks 42 and is then
threaded into
the base block 36. Alternatively, the face block portion 40, spacer portion 38
and base
block 36 may be made as a unitary, or one piece construction, of cold rolled
steel, tool steel
or other suitable alloys or metals.
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The tool 10 also includes four grooved rollers 50 which are rotatably mounted
within one of the roller cavities 34. Each of the rollers SO is rotatably
mounted on a roll
pin 52 secured within the head 30 and is rotatable about a longitudinally
extending
centerline axis (not shown) of the corresponding one of roll pins 52. Each of
the roll pins
52 extends between an adjacent pair of the face blocks 44 and may be retained
within head
30 by the positioning of bolts 46 within head 30. Alternatively, the roll pins
50 may be
secured within head 30 by other means including set screws or a slight press
fit within head
30. Two of the grooved rollers, designated as 50A and 50B in Fig. 2, are
rotatable in a
substantially vertical plane. The other two rollers, designated as 50C and 50D
in Fig. 2,
are rotatable in a substantially horizontal plane. Each of the grooved rollers
50 includes
a periphery 54 which extends into the interior cavity 32, as best seen in Fig.
2, and is
configured to engage a portion of the outer surface of a shaped tube, such as
the square
tube I2 shown in Fig. 5.
In the illustrative embodiment the periphery 54 of each of the grooved rollers
50
includes a generally V-shaped portion 56 which is effective for engaging one
of the corner
portions of a square tube to be reduced, such as corner portions 18 of tube
I2. The
periphery 54 of each roller 50 further includes a pair of beveled end surfaces
58 extending
from opposite sides of the centrally disposed, V-shaped portion 56. As best
seen in Fig.
2, each of the end surfaces 58 of each of the grooved rollers 50 is disposed
in close
proximity with one of the end surfaces 58 of an adjacent one of the grooved
rollers 50. For
instance, one of the end surfaces 58 of roller 50A is disposed in close
proximity with one
of the end surfaces 58 of roller 50C, while the other end surface 58 of roller
50A is
disposed in close proximity with one of the end surfaces 58 of roller 50D. At
the various
interface locations, the end surfaces 58 of adjacent rollers 50 are
substantially parallel to
one another as shown in Fig. 2. The end surfaces 58 may be slightly spaced
from one
another, or may actually touch one another at the interface locations.
Due to the positioning of the rollers 50 relative to one another, the V-shaped
portions 56 of the rollers 58 combine to create a substantially square shaped
entrance 60
of the interior cavity 32 of the head 30. The size of entrance 60 is less than
the outside
dimensions of the square tube to be reduced, thus forcing the end of the tube
to engage
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each of the rollers SO thereby causing an end reduction, such as that shown
with respect
to end portion 20 of tube 12. The maximum longitudinal length of the reduced
end portion
20 of tube 12, may be determined primarily by a longitudinal length 62 of the
spacer
blocks 42.
The tool 10 further includes a mandrel 64 disposed within the interior cavity
32 of
the head 30. The mandrel 64 is preferably a solid metal rod having a polygonal
cross-
section, which may vary with the shape of the tube being reduced. In the
illustrative
embodiment, mandrel 64 has a generally square cross-section. As best seen in
Fig. 2, the
mandrel 64 is spaced apart from the periphery 54 of each of the rollers 50.
The required
spacing between mandrel 64 and the rollers 50 varies depending upon a variety
of factors
including the size and wall thickness of the tube being reduced, and the
desired reduction
in size of the end of the tube. Mandrel 64 prevents the reduced end portion of
the tube
being reduced, such as portion 20 of tube 12, from collapsing, or deforming
inward due
to the force exerted by rollers 50 on the tube. Mandrel 64 includes a first,
forward end 66
which protrudes forward from the head 30 and an opposite end 68 which is
secured to the
head 30 by conventional means such as a bolt 70, or other suitable means. The
mandrel
64 extends longitudinally through the face block portion 40, the spacer
portion 38 and into
the base block 36. Mandrel 64 includes a plurality of longitudinally extending
chamfers
74, with one being formed in each of the corners of the polygonal cross-
section, to
facilitate engagement with the tube being reduced. More particularly, the
chamfers 74 are
required to minimize the drag effect due to contact between the mandrel 64 and
the tube
being end reduced as mandrel 64 is inserted into the hollow interior of the
tube, such as the
interior portion 14 of tube 12.
The tool 10 may optionally include a means for maintaining a substantially
uniform
shape of the end of the tube being reduced. For instance, as shown with
respect to tube 12,
reduced end portion 20 has a substantially uniform square shape which is
substantially the
same as that of the remaining portion 22 of tube 12. In the illustrative
embodiment, the
means for maintaining a substantially uniform shape of the end of the tube
being reduced,
comprises a rake 76 which is disposed within the interior cavity 32 of the
head 30. The
rake 76 is made from a block of cold-rolled steel, tool steel, or other
suitable material. As
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shown in Fig. 1, each of the spacer blocks 42 may include a vertically
extending groove
78 which is sized to accept one side of the rake 76. Rake 76 is then fixedly
attached to the
base block 36 by conventional means, such as a pair of bolts 80.
Rake 76 includes an aperture 82 extending therethrough, with the aperture 82
communicating at a forward end thereof with the interior cavity 32 of the head
30. The
aperture 82 includes a forward, flared portion 84 and a tapered bore 86
extending
longitudinally rearwardly from the forward, flared portion 84. The tapered
bore 86 has
a shape which substantially matches that of the tube being reduced and
gradually reduces
in size from a forward to a rearward end of the bore 86. In the illustrative
embodiment
IO bore 86 has a generally square shape. The inventor has determined that in
certain
applications the end of the tube being reduced, such as end portion 20 of tube
12, may tend
to flare outward locally after the end portion 20 has passed through the
rollers 50. As the
end portion 20 progresses through the head 30, the end portion 20 engages the
rake 76.
The forward, flared portion 84 is effective for receiving the end portion 20,
even if it has
flared outwardly somewhat, and serves as a guide which forces the end portion
20 into the
tapered bore 86. The tapered bore 86 is effective for correcting any outward
flaring of the
end portion 20 which may have occurred, so as to maintain a substantially
uniform square
shape of the end portion 20. After the end portion 20 of tube 12 has reached
the rear end
of the tapered bore 86, tube 12 may be retracted and removed from tool 10,
with the
reduction of the end portion 20 being completed.
Figs. 6-9 illustrate a tool 100 according to a second embodiment of the
present
invention, which is configured to achieve an end reduction in a hollow, shaped
metal tube,
such as the substantially rectangular metal tube 102 shown in Fig. 10. Tube
102 has a
hollow interior 104 and an exterior surface 106, including six corner portions
108. Tool
100 is effective for reducing an end portion 110 of tube 102, which is reduced
in size
relative to a remaining portion 112, but retains the same, substantially
rectangular shape
as the remaining portion 112. The reduced end portion 110 of the rectangular
tube 102 may
be inserted into another rectangular tube 114 of the same size.
Tool 100 includes a head 116 having a longitudinally extending interior cavity
1 I8
and a plurality of roller cavities 120 communicating with the interior cavity
118. Similar
T ___ __. ._. __. .. _ .. ~_ _.~_.~.._..... T_
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to tool 10, the head 116 of tool 100 includes a base block 122, a spacer
portion 124
connected to base block 122, and a face block portion 126 connected to the
spacer portion
124. In the illustrative embodiment, the face block portion 126, spacer
portion 124 and
base block 122 are fixedly attached to one another by conventional means such
as bolts
128. Alternatively, the face block portion 126, spacer portion 124 and base
block 122 rnay
be made as a unitary construction from a material such as cold-rolled steel,
tool steel or an
equivalent material. The base block 122, spacer portion 124 and face block
portion 126
combine to define the interior cavity 118 of the head 116. In the illustrative
embodiment,
the spacer portion 124 comprises a single spacer block, but alternatively may
include a pair
of laterally spaced blocks. The face block portion 126 includes the roller
cavities 120 and
a plurality of face blocks 130 configured and disposed relative to one another
to define the
roller cavities 120.
Tool 100 further includes a plurality of the grooved rollers 50, described
previously
with respect to tool 10, which are rotatably mounted in the face block portion
126 of the
head 1 I6. Similar to tool 10, each of the rollers SO of tool 100 is rotatably
mounted on a
roll pin 52 which is secured within an adjacent pair of the face blocks 130.
However,
unlike tool 10, each of the grooved rollers 50 of tool 100 is rotatable about
a plane which
is inclined relative to vertical. The periphery 54 of each of the grooved
rollers 50 of tool
100 extends into the interior cavity 118 and engages a corner portion of the
rectangular
tube being reduced, such as the corner portions 108 of tube 102 as tube 102
passes into the
interior cavity 118 of head 116. Unlike tool 10, only one of the beveled end
surfaces 58
of each roller SO is disposed in close proximity to the beveled end surface 58
of an adjacent
grooved roller 50. The remaining beveled end surface 58 is disposed in close
proximity
to one of a pair of flat-area rollers 132 which are included in the tool 100.
Tool 100 further includes a mandrel 134 having a forward end 136 protruding
forward from the head 116 and an opposite end 138 which is secured to the base
block 122
by conventional means such as a pair of bolts 139. The mandrel 134 extends
along a
longitudinally extending centerline axis 140 of tool 100, through the face
block portion
126, spacer portion 124 and into the base block I22. Mandrel 134 preferably
comprises
a solid rod having a polygonal cross-section. More particularly, mandrel 134
preferably
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has a generally rectangular cross-section. As best seen in Fig. 7, the mandrel
134 is spaced
apart from the grooved rollers 50 and the flat-area rollers 132. The required
spacing
between mandrel 134 and rollers 50 and rollers 132 varies with the factors
discussed
previously with respect to the mandrel 64. The forward end 136 of mandrel 134
includes
a pair of longitudinally extending lead-in chamfers 135 formed in the two
relatively short
sides of mandrel 134, and a pair of longitudinally extending lead-in chamfers
137 formed
in the two relatively long sides of mandrel 134. As with mandrel 64, the lead-
in chamfers
135 and 137 of mandrel 134 are required to minimize the drag effect due to
contact
between the mandrel 134 and the tube being end reduced such as tube 102.
Mandrel 64
further includes a pair of longitudinally extending grooves 180. One of the
grooves 180
is formed in an upper surface 182 of mandrel 64 and the other groove 180 is
formed in a
lower surface 184 of mandrel 64. The grooves 180 are aligned with, and have a
shape
which is complimentary to a portion of one of the flat-area rollers 132 as
subsequently
discussed.
As shown in Figs. 6 and 7, one of the flat-area rollers I32 is disposed above
the
mandrel 134, while the other flat-area roller 132 is disposed below the
mandrel I34. Each
of the flat-area rollers 132 has a periphery 142 which is effective for
engaging at least a
portion of one of the relatively long sides I44 of the substantially
rectangular tube 102 as
the tube 102 passes into the interior cavity 118 of tool 100. Both of the flat-
area rollers 132
are rotatably mounted on one of the roll pins 52 which are secured within each
one of an
adjacent pair of the face blocks 130. Each of the flat-area rollers 132 is
rotatable in a
substantially vertical plane. In the illustrative embodiment, the periphery
142 of each of
the flat-area rollers includes a pair of substantially cylindrical end
portions 146 and a
raised, substantially cylindrical central portion 148 extending laterally
between the end
portions 146. The diameter of the raised central portion 148 is larger than
that of either of
the end portions 146, which are preferably equal to one another, such that the
raised central
portion 148 protrudes or extends radially beyond the end portions 146. Each of
the raised
central portions 148 engages a portion of one of the long sides 144 of the
rectangular tube
102 as tube 102 enters the interior cavity 118 of the head 116. Each of the
raised central
portions 148 has a shape which is complimentary to the shape of the adjacent
one of the
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grooves 180 of mandrel 64. The raised central portions 148 of the flat-area
rollers 132
cooperate with the grooves 180 in mandrel 64 to fiurther work the tube being
end-reduced,
i.e, in additional to the work performed by the rollers 50. The combination of
the raised
central portions 148 of the flat-area rollers 132 and the grooves 180 of
mandrel 64 create
a local, substantially uniform depression in the upper and lower surfaces of
the tube being
end reduced. These local depressions do not adversely affect the tube being
end reduced.
Alternatively, the raised central portion 148 may be omitted from each of the
flat-area
rollers 132, so that the periphery 142 of each roller 132 has a substantially
cylindrical
shape with uniform diameter throughout. In this instance, the periphery 142 of
each roller
132 may engage substantially all of one of the long sides 144 of tube 102 as
tube 102
passes into the interior cavity 118. The incorporation or exclusion of the
raised central
portion 148 in each of the flat-area rollers 132 and the incorporation of
grooves 180 in
mandrel 64 depends upon the size, wall thickness and the desired end
reduction, of the
rectangular tube being end-reduced. The incorporation of the raised central
portions 148
in the flat-area rollers 132 and grooves 180 in mandrel 64 is particularly
useful when the
long sides of the rectangular tube being end-reduced are significantly greater
in length than
the short sides of the rectangular tube.
Similar to tool 10, tool 100 may optionally include a means for maintaining a
substantially uniform shape of the end of the tube being reduced. For
instance, as shown
with respect to tube 102, the reduced end portion 110 has a substantially
uniform
rectangular shape which is substantially the same as that of the remaining
portion 112 of
the tube 102. In the illustrative embodiment, the means for maintaining a
substantially
uniform shape of the end of the tube being reduced, comprises a rake 150 which
is
disposed within the interior cavity 118 of the head 116. In the illustrative
embodiment,
cavity 118 does not extend through the upper surface of head 116, and
accordingly, rake
150 is inserted into the spacer portion 124 of head 116, prior to attaching
the spacer portion
124 and the base block 122 to one another. The rake 150 may then be fixedly
attached to
the base block 122 by conventional means such as one or more bolts (not
shown). In the
instance when the various components of head 116 are made as a unitary
construction, the
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interior cavity 118 may extend through either the upper or lower surface of
head 116 to
permit installation of rake 150.
The rake 150 is made from a block of cold-rolled steel, tool steel or other
suitable
material. The function of the rake 150 is substantially the same as that of
rake 76 of tool
S 10. Rake 150 includes an aperture 152 extending therethrough, with the
aperture 152
communicating at a forward end thereof with the interior cavity 118 of the
head 116. The
aperture 152 includes a forward, flared portion 154 and a tapered bore 156
extending
longitudinally rearwardly from the forward, flared portion 154. The tapered
bore 156 has
a generally rectangular shape which gradually reduces in size from a forward
to a rearward
end of the bore 156. As the reduced end of a shaped tube, such as end portion
110 of tube
102, passes through the head 118 the end portion 110 engages the rake 150. The
forward,
flared portion 154 is effective for receiving the end portion 110, even if it
is flared
outwardly somewhat, and serves as a guide which forces the end portion 110
into the
tapered bore 156. The tapered bore 156 is effective for correcting any outward
flaring of
the end portion 110 which may have occurred, so as to maintain a substantially
uniform
rectangular shape of the end portion 110. After the end portion 110 of tube
102 has
reached the rear end of the tapered bore 156, tube 102 may be retracted and
removed from
tool 100, with the reduction of the end portion 110 being completed.
In operation, either tool 10 or tool 100 may be used to reduce the end of a
shaped,
hollow metal tube as discussed previously. The manner in which either of the
tools 10 or
100 engage the corresponding shaped, hollow tube, so as to effect an end
reduction in the
tube, may be better understood with reference to Fig. 11. For purposes of
discussion tool
I00 is shown in Fig. 1 l, although the subsequently described system and
method may also
be used in conjunction with tool 100.
Tool 100 is slidingly mounted to a support structure 160 having a base 162 and
a
plurality of legs 164 attached at one end to the base 162 and having the
opposite end
resting on a floor 166, or other suitable surface, of a work area. Also for
purposes of
discussion, Fig. 11 illustrates the substantially square tube 102 prior to the
reduction of the
end portion 120 as shown in Fig. 5. A portion of tube 102 is secured in a pair
of clamping
blocks 168, with a lower one of the clamping blocks 168 being fixedly attached
to the base
14
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162 of support structure 160. The clamping blocks 168 encapsulate a portion of
the tube
102, holding it in place during the swaging or end reduction process. A
clamping force
may be applied to the upper one of the blocks 168 by a hydraulic actuator 169.
Alternatively, a clamping force may be applied to blocks 168, and the portion
of tube I02
encapsulated by blocks 168, by other conventional means. Tube 102 is oriented
within the
clamping blocks 168 to properly engage the grooved rollers 50 of the tool 100.
An end
170 of the tube 102 is disposed in an abutting relationship with a stop block
171 which is
fixedly attached, by conventional means, to the base 162 of the support
structure 160.
The tool 100 is connected to an actuating means, indicated generally at 172,
which
is effective for translating the tool 10 in a direction 174 so that the tool
100 engages the
tube 102. In the illustrative embodiment, the actuating means 172 comprises a
hydraulically actuated cylinder which is connected to tool 100. The hydraulic
cylinder
may be directly attached to tool 100 or alternatively may be attached to a
plate which in
tum is attached to tool 100. The hydraulic cylinder may be powered by a
hydraulic motor
(not shown) and associated conduits (not shown) for delivering the hydraulic
fluid to and
from the actuating means 172. Alternatively, the actuating means 172 may
comprise a
variety of other conventional actuation means, such as one or more pneumatic
cylinders,
a servo motor, worm gear, etc. which are connected to the tool 100 and are
effective for
translating the tool 100 in direction 174. The actuating means may further
include a guide
means 176 attached to tool 100 for maintaining the proper orientation of the
tool 100 as
it is actuated. The actuating means 172 may further include a control means,
(not shown)
for controlling the distance which tool 100 translates, and accordingly, the
length of the
end reduction of tool 102 which is achieved.
While the foregoing description has set forth the preferred embodiments of the
present invention in particular detail, it must be understood that numerous
modifications,
substitutions and changes can be undertaken without departing from the true
spirit and
scope of the present invention as defined by the ensuing claims. For instance,
although
tool 10 has been illustrated with the included rollers 50 configured and
positioned relative
to one another so as to achieve an end reduction in a substantially square
tube, the rollers
SO may be repositioned relative to one another within tool 10 so as to achieve
an end
CA 02283734 1999-09-15
WO 98/41338 PCT/US98105434
reduction in a substantially rectangular tube. Furthermore, the periphery 58
of the rollers
50 of tool 10 may be modified so that the plurality of rollers 50 of tool 10
substantially
encapsulate an oval-shaped tube so as to achieve an end reduction in the oval-
shaped tube.
Furthermore, tool 10 may include a plurality of rollers which are positioned
relative to one
another and include peripheries which are configured so that the plurality of
rollers
encapsulates a D-shaped tube so as to achieve an end reduction in the D-shaped
tube.
Also, although tool 100 has been illustrated with the included rollers 50 and
rollers 132
configured and positioned relative to one another to achieve an end reduction
in a
substantially rectangular tube, one or more of the rollers 50 and 132 may be
repositioned
and/or reconfigured so that the combination of rollers 50 and 132
substantially encapsulate
an oval or a D-shaped tube so as to achieve an end reduction in the oval or D-
shaped tube,
respectively. It is also envisioned that an end reduction in tubes having
other shapes may
be achieved by a tool embodying the principle of the present invention. The
invention is
therefore not limited to specific preferred embodiments as described, but is
only limited
as defined by the following claims.
16
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